Method of making studs



c. KAUFMAN METHOD QF MAKING STUDS I Filed Sept. 3, 1925' wmzfo 1,- I

a mm j j Patented Feb. 8, 1927;-

UNITED STATES;

CHARLES KAUFMAN, or" CLEVELAND, 01110.

I METHOD. OF MAKINQ STUDS Application filed September This invention relates to a method of making studs and has for its chief object the pro-.

vision of a method by. which more accurate and stronger studs are produced and which is more economical than/the commonly employed method of producing them.

Heretofore studs have generally been produced on stud making machines which turn down, the'stock to the required dian'ieter or diameters and-then cut the thread on both end portions. Generally the studs are then heat treated to give-them the requisite degree of hardness and strength. This method is not economical, in view of the amountof stock that is wastedin forming the studs and furthermore the studs lack accuracy, for the reason that in the'heat treatment the threads are often distorted,

In carrying out the present invention the disadvantages or objections to the commonly employed method are overcome by forming the studs without any wastage of material andwithout the necessity of heat treatment. In accomplishing-these results sto(i( of suitable size'is cut to the desired length and is so treated that both its end portions to be threaded are drawn out so as to be reduced to the pitch diameter of the thread to be formed and are, of course, simultaneously lengthened. Next, the threads are rolled on the reduced-end portions completing the formation of the studs.

The invention may be further briefly summarized as consisting in thestcps of the im- I proved methods that will be. described in the specifications pended claims.

In the accompanying sheet of drawings. illustrating h manner ,in whichthe methodrlf and from each 'otherand generally one is fixed and the other movable. The 'die 12 may andset forthin the ap- 40 is carried out, lshows a length of stock as it appears prior to thetreatnient. Figr2 is a similarview" 'after the end portions have been reduced and lengthened. v.fFig. is a similar view after the threads-have been rolled onto the reducedlend portionsor of Y the finished stud and Fig. '4 'is {a sectional view showing in 'a somewhat. conventional .man'ner dies which may be used in formingthe blankof Fig. 2 by reducing and lengthening the stock of Fig. 1. I

In. carrying out my invention, wire or. red of-given diameter and indeterminate 3, 1925! Serial N0.-54,275.

length is utilized and preferably cold drawn wire is employed, as it is more accurate in size and gii- 'es increased strength, the advantage of which will appear presently; The blanks. with reduced end portions and ready for the threading are formed very rapidly in asuitable machine, the stock being fed from a coil or reel to a cut-off mechanism which cuts the stock to the desired length,-such as is indicated in Fig. 1, it being understood, of course, that studs of any desired length may be formed: r

The cut-oft section 10 is then carried over to suitable mechanism which produces the blankllof Fig. 2, this blank having a mid- (lle portion 11 and reduced end portions 11*- r and 11. The relative lengths of the middle smaller thread than the other, such end will' be reduced to a smaller diameter, equal-to thereon.

smaller diameter than the end 11".

In reducingthe end portions ofthe blank the pitch diameter of the thread-to befojrmed In this instance the en'djll isshown in Fig. 2 as reduced to a somewhat apair 'of-dies-are employed forming a part i of the machine having the cut-off mechanism', suitable dies being illustrated at 12 and 13.

These diesv are relatively movable toward be regarded as the fixed die and the, die 13.is

the movable die. --These dies are provided with opposed cavitiesihaving outer portions 12 and 13*, which in diameter correspond to the diameter of the stock 10 and of the middle portion 11 of the blank 11 and inwardly of the portions 12*. and 13*, the die cavities have reduced-portions 12 and 13.

these corresponding to the diameters to which the end' portions 11" and 11 are to be reduced; additionally the dies are provided with adjustable gauges12 and 13, which determine the lengths of the reduced portions 11 and 11 and also serve as e'ectors.

From the cut-off mechanism the length of stock is carried over between the dies 12 and 13 into line with the cavities therein and immediatelythereafter the dies close and in closing the end portions of the stock are forced into 1e reduced portions 12 and 13 of the die ca %ties, so as to reduce and lengthen both end portions with an action similar to that in a drawing or extruding process. This completes the formation of blank of Fig. 2, which is ejected from the dies as soon as they move apart. In this manner the blanks are formed rapidly and with great accuracy and it is an iniportant feature that the red'uced portion slam hardened by the drawing or lengthening and reducing action of the dies.

In forming the cavities n the dies 12 and 13 it is preferable that the outer or larger portion of the cavity in one die be longer than the corresponding portion of the other die, so that themajor portion of the stock which is not reduced in diameter will be received or held in one die cavity. This is illustrated in Fig. 14 wherein the major part of the middle portion 11,,of the blank is received in the cavity of the die or plunger 13. This arrangement avoids all liability of the stock buckling between the dies and-it may be stated at this point that the blanks may be formed in .the manner stated without any flashing or other deformation in that a part of the stock which forms the middle p rtion 11*.

From the blank 11 formed as above described, the finishedstud 14, Fig. 3 is produced, the same having an unthreaded middle portion 14* and threaded end ortions 14 and 14. This is preferably. one by rolling the threads on the reduced end portions of the blank, which end portions were, 'as previously stated, reduced to tlie pitch diameter or diameters of the threads to be formed thereon.

- When the'threads are rolled on the blanks the studs are completed and ready for use,-

no heat treatment being required to harden and strengthen them, due to the skin or surface hardening imparted to the blanks by drawing out the end portions in reducing them to the pitch diameter or diameters of the threads to be formed. 'This is true particularly when cold drawn stock isemployed which is somewhat harder and tougher than hot drawn stock.

It will be seen that there is no wastage of material in forming the studs by my improved method and that the studs will.be formed accurately and uniformly -.to the right dimensions, particularly as my method eliminates the necessity of heat treatment which heretofore has frequently warped the threads. Consequently the objects of the sponding to the diameter of the middle portion of the blank, but my invention can be used substantially as effectively if the stock is slightly over-sized or undersized. If it is Slightly over-sized, the stock will be forced into the outer or largerportions of the die cavities slightly reducing the size of.

the stockto the extent of the oversize tolerance. If. the stock is slightly undersized 1t 'will be expanded slightly in the outer. pormiddle tions 'of the die cavitiesto form the portion-11 of the blank. Generally, how ever, as already stated, the diameter of the middle portion of the stock which forms the middle portion 11 of the blankremains unchanged. 1

I wishsto repeat that the end portions of the stock may be reduced to the same diameter if desired and each reduced end portion as well as the middle portion may have'any length desired.

I do not desire to be confined to any par-' 'ticular means or apparatus shown for carrying out the method and aim in my claims to cover all modifications which donot involve a departure from the spirit and scope of my invention. 1

Having described my lnvention, I claimlength of studs which 1. The method of making studs from a comprises in one drawing operation lengthening and reducing both end portions of a length of stock to the pitch diameter or diametersv of the threads to be formed by forcing said portions of the stock by endwise pressure into the openings of'a pair of drawing dies,-while maintaining the mlddle portion at substantially vits original diameter and rolling the threads on the reduced end portons.

3. The method of making studs which comprises in one operation drawing out the end portions of a length of stock so that each end portion is reduced to the pitch diameter of the thread to be formed thereon by forcing said portions by pressure exerted endwise on the stock into openings of drawing dies and then forming the threads on the reduced portions.

In testimony whereof, I hereunto aflix my signature.

CHARLES KAUFMAN. 

